Qardash and Al-Baghdadi share a common bond, having both served as officers in the Iraqi Army under Saddam Hussein.

Despite numerous claims about his death in the past few years, al-Baghdadi's whereabouts remain a mystery.

Many of his top aides have been killed, mostly in US-led coalition airstrikes. He is among the few senior IS commanders still at large after two years of heavy battlefield losses in Iraq and Syria that saw the fall of the so-called caliphate.

Some reports have placed the "invisible sheikh" in Iraq's Al Anbar province, west of Baghdad.